Neuroendocrine tumours (NETs) are rare, heterogeneous neoplasms, whose nomenclature stems from their capability to secrete hormones. We present two cases – a 63-year-old male with a grade 2 (Ki-67 index 17%) metastatic midgut NET, and a 43-year-old female with a grade 2 (Ki-67 index 5%) metastatic pancreatic NET. Both patients suffered life-threatening diarrhoea in the context of hepatic metastases. The first case examines a patient with refractory carcinoid syndrome who suffered intractable diarrhoea despite all treatment modalities, including long acting somatostatin analogue, short acting somatostatin top up, telotristat, interferon and Lutate (177Lu-DOTATATE, peptide receptor radionucleide therapy (PRRT)). The second patient had a Vasoactive Intestinal Peptide (VIP) secreting pancreatic NET with liver metastases, who endured multiple intensive care stays as a result of severe metabolic and electrolyte disturbance from high output diarrhoea (> 7 litres per day at her peak), ultimately responded to corticosteroids and Lutate. We review the case histories highlighting the clinical presentation and discuss the pathophysiological mechanisms underlying diarrhoea in NETs, appropriate diagnostic investigations and differential diagnoses. This report reviews the approaches in multimodality management options for severe refractory diarrhoea in midgut and pancreatic NETs, highlighting available treatment options and a recommended treatment pathway to minimize the impact of this symptom on patients’ quality of life.